you want to create 2 sub-lists, of unknown size, so use AtrrayLists
java.util.List days31 = new java.util.ArrayList();
java.util.List daysLessThan31 = new java.util.ArrayList();
iterate your months array
if(days = 31) days31.add(monthname)
else daysLessThan31.add(monthname)
now iterate sub-list days31
System.out.println((
String)days31.get(x));
now iterate sub-list daysLessThan31
System.out.println((String)daysLessThan31.get(x));